The common tube clamp includes a flat base member or first leg and a flat closure member or second leg that extends in substantial parallelism to said base. The base and closure member are integrally formed with one another and are interconnected at their respective proximal ends by a flexible interconnecting means having the configuration of a return bend.
The first leg or base member terminates at its distal end in a substantially orthogonally disposed latch member having plural transversely disposed, equidistantly spaced teeth members formed on a proximal side thereof.
The second leg or closure member terminates in a leading edge that is adapted to selectively engage the interdental spaces of the toothed latch member and said leading edge is thus understood to function as a catch means.
Tube-pinching protuberance members are formed on the underside and topside, respectively, of the closure member and the base member, about mid-length thereof, in confronting relation to one another.
The clamp is carried by a tube that extends through an aperture formed in the return bend part of the clamp and that is positioned between the opposing protuberances. The tube is constricted to any desired degree by manually compressing the clamp at its leading end; the catch means at the leading free end of the closure member successively engages the teeth formed on the latch member until the desired amount of flow restriction is achieved and the desired position is maintained when the clamp is released by the interdental engagement of the catch and the teeth of the latch member. The clamp is released by lightly compressing the closure member to momentarily release the pressure between the latch and catch and displacing the flexible tooth-carrying latch member away from said catch to allow the closure member to resume its position of repose.
Earlier patents showing such tube clamps include U.S. Pat. Nos. 4,097,020 to Sussman and 3,942,228 to Buckman, et. al.
If carefully used, the tube clamps heretofore known are adequate to perform their intended function, especially if they are of metallic construction. Problems may arise, however, when the clamps are used carelessly. Health care professionals, e.g., are often required to handle very large workloads and must accomplish many tasks quickly. As a consequence, a nurse or doctor, intending to shut off an intravenous feed, may quickly squeeze the tube clamp very hard and walk away without visually inspecting the clamp to determine whether or not fluid flow has actually stopped. The common tube clamp, described above, is susceptible to skewing when closed with less than due care, especially if it is of plastic construction, as are most modern clamps. When skewing occurs, the tube is only partly pinched by the confronting protuberances and flow of liquid therethrough may continue. Skewing is caused by a failure to maintain the alignment of the catch and the latch, i.e., at the completion of a skewed closing, the longitudinal axis of the closure member is disposed at an angle relative to the longitudinal axis of the base member, and the protuberances formed integrally with said parts are misaligned with respect to one another and a full pinching action is not achieved.
An improved tube clamp is needed that would function properly even when closed in a careless manner, but the prior art, when considered as a whole, neither teaches nor suggests how the existing clamp could be improved.